Final answer:
The cerebral cortex (Option B) is the key brain structure for learning new things, responsible for cognitive functions including processing information, learning, and memory. The hippocampus also plays a critical role in the formation of long-term memories and emotions. The correct option is B.
Step-by-step explanation:
The key brain structure for learning new things is the cerebral cortex (Option B). The cerebral cortex is a critical area for processing information, learning, memory, and other cognitive functions. It is divided into four primary lobes: frontal, temporal, occipital, and parietal, each responsible for different aspects of cognitive processing.
Subcortical structures such as the basal ganglia, hippocampus, and amygdala play supportive roles in learning and memory. The hippocampus, in particular, is essential for the formation of long-term memories and emotional responses.
Other structures like the medulla oblongata are involved in controlling vital functions, the hypothalamus in maintaining homeostasis, and the basal ganglia in movement control, but they are not primarily responsible for learning new things like the cerebral cortex is. The correct option is B.